// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
using Google.ProtocolBuffers.DescriptorProtos;

namespace Google.ProtocolBuffers.Descriptors {
  /// <summary>
  /// Describes a single method in a service.
  /// </summary>
  public sealed class MethodDescriptor : IndexedDescriptorBase<MethodDescriptorProto, MethodOptions> {

    private readonly ServiceDescriptor service;
    private MessageDescriptor inputType;
    private MessageDescriptor outputType;

    /// <value>
    /// The service this method belongs to.
    /// </value>
    public ServiceDescriptor Service {
      get { return service; }
    }

    /// <value>
    /// The method's input type.
    /// </value>
    public MessageDescriptor InputType {
      get { return inputType; }
    }

    /// <value>
    /// The method's input type.
    /// </value>
    public MessageDescriptor OutputType {
      get { return outputType; }
    }

    internal MethodDescriptor(MethodDescriptorProto proto, FileDescriptor file,
        ServiceDescriptor parent, int index) 
        : base(proto, file, parent.FullName + "." + proto.Name, index) {
      service = parent;
      file.DescriptorPool.AddSymbol(this);
    }

    internal void CrossLink() {
      IDescriptor lookup = File.DescriptorPool.LookupSymbol(Proto.InputType, this);
      if (!(lookup is MessageDescriptor)) {
        throw new DescriptorValidationException(this, "\"" + Proto.InputType + "\" is not a message type.");
      }
      inputType = (MessageDescriptor) lookup;

      lookup = File.DescriptorPool.LookupSymbol(Proto.OutputType, this);
      if (!(lookup is MessageDescriptor)) {
        throw new DescriptorValidationException(this, "\"" + Proto.OutputType + "\" is not a message type.");
      }
      outputType = (MessageDescriptor) lookup;
    }
  }
}
